Membrane biogenesis will be studied in Spirillum itersonii with emphasis on the incorporation of cytochromes and the terminal enzyme of heme biosynthesis, ferrochelatase. Methods will be sought for the isolation and for separation and identification of membrane proteins by gele electrophoresis. Ferrochelatase, which is readily released from Spirillum membrane, will be purified and its properties compared with the functional bound form. Attempts will be made to reconstitute the soluble enzyme with depleted membrane. The membrane proteins of a mutant lacking ferrochelatase will be examined. The regulation of enzymes of heme biosynthesis will be studied with ferrochelatase mutant. A search will be made for mutants with other blocks in heme biosynthesis with a view to exploiting them for studies of regulation. Membrane biogenesis in Staphylococcus aureus will also be investigated with particular emphasis on kanamycin resistant mutants which require heme.